The utilization of information received during a silent interval between ringing signals, including the Individual Calling Line Identification (hereinafter CID) number, is now being incorporated into new private or subscriber-owned communication systems (e.g., key or private branch exchanges (PBX) systems). Many private or subscriber-owned communication systems exist in which the extension number of a system calling station is transmitted to the called system station. One known subscriber-owned communication system also transmits the CID number of a network calling station to the called station between successive ringing signals.
Undesirably, however, this CID number or other information is only made available at the called station set and is unavailable once various calling features are activated, e.g., delayed ringing, call transfer, etc.